Sandpapering-machine.



PATENTED OCT. 29. 1907.

APPLICATION FILED MAY 14,1906.

2 SHEETS-SHEET 1.

PATENTED OCT. 29, 1907.

J. BLACK.

SANDPAPERING MACHINE.

APPLIOATIOH FILED MAY 14*,1806.

2 SHEETS-SHEET 2.

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JOHN BLACK, OF MENDOTA, ILLINOIS.

SANDPAPERING-MACHINE Specification of Letters Patent.

Patented 001;.29, 1907.

Application filed May 14 1906- Serial No. 316,671.

To all whom it may concern:

Be it known that I, JOHN BLACK, a citizen of the United States, residing at Mendota, in the county of Lasalle and State of Illinois, have invented certain new and useful Improvements in Sandpapering-Machines, of which the following is a specification. I This invention relates to power operated sand papering machines for finishing furniture and other wooden articles and has for its object to provide mechanism for moving a belt of sand paper without bringing any appreciable tension to bear on the sand paper belt which might tend to break the belt and thus render it unlit for further use.

In sand paperingmachines of the ordinarycharacter, a belt of sandpaper is driven under considerable tension by power pulleys in much the same way that an ordinary power transmission belt is driven, but this method of actuating the sand paper is objectionable not only on account of the fact that the sand paper belt is liable to break but also by reason of the fact that the tension on the belt prevents it from conforming to the contour of the object acted upon, which greatly impairs its usefulness. By employing a slack belt the pressure of the object acted upon serves to compress the slack belt around the surface of the object, which provides a much greater abrading surface, increases the speed of the sand paper operation, and results in a much more even and uniform sand papering than would be the case if the belt were tight and in flat condition. This is more especially true of the sand papering of round objects like Indian clubs, pieces of furniture and other objects of a more or less irregular shape. Another object of the invention is to provide means for regulating the position of the belt, thereby adapting it to act upon articles of different shape and character. Further objects of the invention are to provide means for regulating the speed of travel of the sand paper belt to improve the construction and arrangement of the operating pad for supporting the sand paper at the operative point, and to improve generally the construction and operation of the machine as a whole and the several par? wifrt'lf.

The ci ion consists of the features of construction no.1 ion of parts hereinafter described and lai i.

in the drawings illustrating the invention Figure 1 is a from elevati nr of the sand papering machine; Fig. 2 an end elevation of the same; Figs. 3 and 4 views showing the machine adjusted in different positions; Fig. 5-

a detail view showing a supporting at achment for the work; and Fig. 6 an enlarged detail view showing the adjustable head and bearings mounted thereon.

The machine consists of a framework comprising a front support 1 and a rear support 2. The supports are uniform in size and shape and each comprises side up rights 3, an upper cross rail 4 and a lower cross rail 5.

The front and rear supports are spaced and connected by means of upper rails 6 and lower rails 7 forming in effect an open rectangular framework. To the front upper cross rail is secured a guide plate 8 of arch formation provided with an adjusting slot 9. Extending from front to rear of the framework is a shaft 10 having mounted thereon fast and loose pulleys l1 and the shaft is rotatably mounted in journal boxes 12 on the upper 'front and rear rails. The shaft 10 outwardly projects from the framework at a point coincident with the center of curvature of the slotted arched guide bar and the shaft serves as a mounting for a swinging arm 13 which is adj ustable with respect to the arched guide bar and is connected therewith by means of a bolt 14 which passes through the slot and the guide bar and has on its rear end a nut 15 adapted to be loosened when desired to permit the arm to be swung into any desired position. The upper end 16 of the swinging arm is reduced in diameter and has slidably mounted thereon a head 17, the vertical elevation of which can be adjusted by means of an adjusting screw 18 which passes through a lug 19 on the head and is revolubly mounted within a lug 20 on the arm. The adjusting screw can be revolved by means of a wheel 21 for raising. and lowering the head to any desired position. The head is provided in its center with an upwardly projecting inverted U shaped yoke 22, and adjacent to the yoke on either side are perforated ears or lugs 23 which are secured to an upper flange 24 on the head by means of screw bolts 25. The head is further provided with a laterally extending lower linger 26 to which is secured a perforated lower lug 27 bynieans of a screw bolt 28. The center yoke 22 has outwardly projecting therefrom a journal bolt 29 upon which is mounted a supporting roller 30 which may be of concave or convex formation, depending upon the contour of the article intended to be finished. As shown in Fig. 2, the roller is concave but when desired rollers of other formation may be employed. Outwardly projecting from the perforated side ears or lugs 23 are a pair of journal bolts 3 which serve for the mounting of idler guide rollers 532, and-the lower car or lug 27, as shown in Fig. 1, has mounted thereon a lower idler guide roller 33 provided with an outer disk 34 furnishing a flange to prevent the displacement of a sand paper belt 35. The sand paper belt passes arou -l a power wheel 36 mounted on the shaft 10 and aroui. an endless belt 37 of felt or other soft material, which is carried over the center supporting roller and around the upper idler rollers. The endless strip or belt of sand paper is loosely carried by the respective pulley and power wheels and is of sufficient length to sag more or less so that ordinarily the power wheel will be free to revolve within the sand paper belt without moving it.

Below the power wheel 36 are a pair of friction rollers 37 of rubber or other similar substance mounted on a shaft 38 carried between arms 39 pivoted to a stationary rod 40, and the outer {ends of the arms are adapted to be-raised and lowered by means of adjusting screws 41 mounted within a framework 42 which outwardly extends from the front side of the main framework of the machine.

In Figs. 3 and 4 is shown a slightly different arrangement of parts, and in place of the idler rollers 32 and compression roller 30 are employed a pair of guide ro ers 43 journaled between the yoke ends 44 of a vertically extending rod! 45 provided with a collar 46 which collar is secured to one of the perforated ears or lugs 23 on the head of the swinging arm. Immediately above the collid 46 is a table 47 for supporting the work, which table is secured to the rod 45 upwardly extending from which is a contact block 48 over which passes an endless felt belt 49 corresponding to the felt belt 37 hitherto described. In Fig. 4 the rod is adjusted to a horizontal position and the guide roller 33 hitherto described is utilized in addition to the rollers 43 on the ends of the rod 45. X

In 'the adjustment shown in Figs. 3 and 4 all of the essential portions of the machine described withreference to Figs 1 and 2 are employed, but the method of carrying the endless sand paper strip or belt is somewhat modified to adapt the machine for use under somewhat dififerent conditions. In all cases the sand paper belt or strip is normally hung loose over the driving wheel 36 which is allowed to rotate freely without moving the sand paper. When it is desired to begin he sand papering operation, the object to be sand papered is compressed against the belt or strip of sand paper at the point where it passes over the endless belt of felt or other compressible material. The friction rollers 37 are next moved into position to bear tightly against the sand paper and compress it against the revolving power wheel. This immediately takes up the slack and tightens the paper/ belt on the pulling side of the power p of tension, however,

wheel without exerting any pull or tension on the other side of the sand paper belt. In short, the sand paper will be tight pn one side between the work and the power wheel, and loose on the other side; The degree will be largely determined by the pressure exerted in forcing the work against the rapidly power wheel.

moving abrading surface. The motion imparted to the sand paper is due, however, not to the tension thus exerted, but to thefriction or compression rollers which hold the otherwise slack belt into tight contact with the revolvingpower wheel. There is none of the strain on the slack belt thatis necessary and incident to the use of a tight belt which depends upon its own tensile strength to hold it into operative contact with the strength to withstand for long the strain of being stretched tight around a power wheel and at the same time being subjected to the compression to the work to be abraded. Experience has shown that tight belts of sand paper quickly wear out unless mounted on some stronger substance than paper. In the present invention the necessary'frictional contact between the paper belt and the power wheel is secured without strain upon the belt. This arrangement enables the power wheel to be uniformly and constantly rotated and enables the sand paper to remain idle while not in use, which eliminates all wear and tear to which it would otherwise be subjected in starting and stopping the power wheel and Sand paper has not sufficient tensile seaess l in thereby imparting to the paper belt sudden and in jurious pulls or jerks. Under ordinary circumstances, the felt belt, when compressed beneath the sand paper strip, will travel around with the sand paper, but it is not necessary that the strip should so travel, since, except for increased friction, substantially the same result would be accomplished if the sand paper were allowed to slip over a stationary piece of felt. The swinging arm or post permits a wide range of adjustment to the parts, and the method of slid ably mounting the head permits variations in the vertical elevation of the sand paper and also permits the amount of slack to be regulated by raising or i lowering the slidable head, as desired. In Fig. 5 is shown a method of using l finishing an Indian club which is carried by a frame 50 and is rotated by means of a flexible shaft 51. In operating upon an object of convex contour, it is advisable I to employ the concave supporting roller, and the slackness of the sand paper strip or belt permits its being compressed at the point of application to conform to the contour of the object to be abraded, which would be impossible or dangerous if the belt were stretched tight, since an unequal pressure exerted on a tight belt or strip of sand paper would tend to break or tear the paper. I

In Figs. 3 and 4 the felt belt or strip is somewhat elongated and the guide rollers are widely separated instead of being placed close together and a fixed block 48 is employed in place of a revoluble roller, but these are l of operating the machine. Figs. 3 and 4 show substantially the same combination of parts adjusted to difien.

ent positions to meet the requirements of different classes of work. In Fig. 4 the work supporting table 47 is dispensed with, for the reason that the sand papering belt, as shown in Fig. 4, travels in a horizontal position so that the table 47, which serves as a convenient support for the work in the machine of Fig. 3, is not required and may be discarded.

Throughout the specification the word felt has been applied to the compressible strip or belt, but it will be understood that some other substance having the properties of felt might be substituted therefor without departing in any way from the spirit of the invention. Furthermore, where the words sand paper are employed in the specification and claims, it will be understood to cover either sand paper, sanded cloth, emery paper," or any other similar substance of an abrar sive nature.

What I regard as new and desire to secure by Letters Patent is:

1. In a sand papering machine, the combination of driving mechanism, a surface affording a support for the article to be abraded, a normally slack strip of sand paper actuated by the driving mechanism and passing over the support and adapted to be compressed by the work against the support and means adjacent to the driving mechanism and adapted to press 'the strip of sand paper against the driving mechanism and holding it in driving contact therewith, substantially as described.

2. In a sand papering machine, the combination or a power wheel, a. compressible surface affording a support for the article to be abraded, a slack belt-or endless strip of sand paper passing around the power wheel and the support and adapted to be' compressed by the machine for the work against the.

support to cause the sand paper ,to conform to the contour of the work, and means adjacent to the power wheel and adapted to press against the outer surface of the sand paper strip and hold the samein driving contact with the power wheel, substantially as described.

3. In a sand papering machine, the combination of a power wheel, an endless compressible belt, a normally slack endless belt or strip of sand paper passing around the power wheel and the endless compressible belt, and-means adjacent to the power wheel and adaptedto press against the sand paper strip and hold it in frictional driving con tact with the power wheel, substantially as described,

4. In a sand papering machine, the tombination of a power wheel, an endless compressible belt, rollers upon which the compressible belt'is mounted, a normally slack endless belt or strip of sand paper passing around the power wheel and the endless belt, and means adjacent to the power wheel adapted to press the sand paper strip or beit against the power wheel and hold it in driving contact therewith, substantially as described.

5. In a sand papering machine, the combination of a power wheel, a surface affording a supp r for the article to be abraded, a slack belt or endoss strip of sand paper passing around the power wheel and the support, and a friction roller adapted to compress the endless belt or strip of sand paper against the power wheel, substantially as described. Q I

6. In a sand paperlng machine, the combination of a framework, a power shaft journaled to the framework, a slotted arched guideway having its center of curvature coincident with the power shaft, an arm adapted to swing around the power shaft as a center and adjustably connected with the slotted guideway, a power wheel on the power shaft, 0. support for the article to be abraded ear ried bythe adjustable swinging arm, a slack belt or strip of sand paper passing around the power wheel and the support, and means adapted to compress the sand paper belt against the power wheel, substantially as described.

7. In a sand papering machine, the-combination of a framework, :1 power shaft journaled to the framework, a. slotted arched guideway having its center of curvature coincident with the power shaft, an arm adapted to swing 8. In a sand papering machine, the combination of a framework, a power shaft journaled to the framework, 0. power wheel mounted-on the shaft, an adjustable arm adapted to swing around the power shaft as a center, an

adjustable connection between the arm and the guideway, a head slidably and adjustably mounted on the arm, a

center supporting roller, end guide rollers, an endless compressible belt carried by the three rollers, a slack belt or strip of sand paper carried around the power wheel and the compressible belt, and a roller adapted to compress the slack belt against the power wheel, substantially as described.

JOHN BLACK.

Witnesses WALTER BLACK, DAVID BLACK. 

